1. Field of the Invention
The present invention relates to an ink-jet printer that performs recording by ejecting ink to a recording medium.
2. Description of the Related Art
Conventionally, there is widely known a serial-type ink-jet printer including an ink-jet head that ejects ink to a recording medium such as a recording paper while moving in a direction perpendicular to a direction in which the recording medium is conveyed. Among such ink-jet printers, in particular, an ink-jet printer disclosed in Japanese Patent Unexamined Publication No. 2005-288753 (FIG. 3) for example includes ink cartridges (ink supply sources) that are fixedly provided and an ink-jet head that can move reciprocatingly in a widthwise direction of a recording paper conveyed. The ink cartridges and the ink-jet head are connected via a flexible tube. Ink supplied from the ink cartridge through the tube is ejected to a recording paper from a nozzle of the ink-jet head that is moving reciprocatingly.
In a case where several ink-jet head eject the same type (color) of ink, a brancher that branches an ink supply path, which is formed of a single tube, into several paths is required in order that ink is supplied from one ink cartridge to several ink-jet heads, respectively. However, when the brancher is provided in an ink-jet head side and moves integrally with the ink-jet head, a distal end portion of the tube connected to the brancher repeatedly receives stress while the ink-jet head is moving.
On the other hand, a diameter of the tube is preferably as large as possible, for the purpose of smooth ink supply from the ink cartridge to the ink-jet head. In general, a tube is often made of a synthetic resin material or the like, which may sometimes cause air to penetrate through the tube and mix into ink in the tube. Therefore, in order to prevent air from penetrating through the tube as much as possible, a wall thickness of the tube is preferably as large as possible. However, when the diameter and the wall thickness of the tube are made large like this, rigidity of the tube is accordingly increased. This makes it difficult that the tube absorbs, by its bending deformation, force acting thereon during movement of the ink-jet head. As a result, the distal end portion of the tube receives larger stress, and therefore a cracking due to fatigue failure or the like is more likely to occur in the tube.